"Is It You" is a song recorded by American singer Cassie for the soundtrack album of the 2008 dance film Step Up 2: The Streets, in which she co-stars as Sophie Donovan. It was made available for digital download on November 13, 2007, through NextSelection Lifestyle Group's venture with Bad Boy and Atlantic Records. The song was written and produced by Ryan Leslie with additional contributor Brent Paschke.

Casandra Elizabeth Ventura, known mononymously as Cassie, is an American singer, dancer, actress, and model. Born in New London, Connecticut, she began her musical career after meeting record producer Ryan Leslie in late 2004, who signed her to his record label, NextSelection Lifestyle Group. Two years later, Ventura released her debut single "Me & U", which was discovered by rapper Sean "Diddy" Combs; Leslie agreed to partner his NextSelection imprint with Combs' Bad Boy Records for the commercial release of her debut album. The song marked the first of her two entries on the Billboard Hot 100, peaking at number three by July 2006.